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whowatch(1) [debian man page]

WHOWATCH(1)						      General Commands Manual						       WHOWATCH(1)

whowatch - console, interactive, process and users monitoring tool. DESCRIPTION
Whowatch is an console, interactive users and process monitoring tool. It displays information about the users currently logged on to the machine, in real-time. Besides standard informations (login name, tty, host, user's process), the type of the connection (ie. telnet or ssh) is shown. Display of users command line can be switch to tty idle time. Certain user can be selected and his processes tree may be viewed as well as tree of all system processes. Tree may be displayed with additional column that shows owner of each process. In the process tree mode SIGINT and SIGKILL signals can be sent to the selected process. Killing processes is just as simple and fun as deleting lines on the screen. Whowatch has no command line options or configuration file. All actions are performed in real time by pressing following keys: Users list mode: 'up' 'down' cursor movement 'i' toggle between user command line and idle time 'c' full command line on/off. Disabling full command line can save CPU time. It can give you also some additional information about process executable. 'enter' view selected user's processes tree. 't' all system processes (init tree) Tree mode: 'up' 'down' cursor movement 'enter' go back to users list 'o' show processes owners 'c' full command line on/off. Disabling full command line can save CPU time. It can give you also some additional information about process executable. 'Ctrl-I' send INT signal to selected process 'Ctrl-K' send KILL signal to selected process PLUGINS
Whowatch has ability to load plugin during program run. Plugin prints information inside details window. Plugins gives flexibility: if some specific information about process, user or system is needed then separate program could be written to obtain such information. Since there are three kinds of deatils window (process, user and system) maximum three plugins can be loaded. Whowatch has very simple API to write plugins. FILES
Program reads /var/log/wtmp, /var/run/utmp. Under Linux program also reads files from /proc directory. Without read access to these files whowatch funcionality will be limited or program will not even start. SEE ALSO
finger(1) ps(1), pstree(1), top(1), w(1), lsof(8), kill(1) killall(1) BUGS
Because lack of ut_pid in utmp and wtmp structures in *BSD systems, program tries to obtain pid of a login shell by analizing processes controlling terminal and processes names. Under some conditions it may lead to incorrect results ie. there will be incorrect processes tree associated with user's session. AUTHOR
Michal Suszycki <>, Tree functions written by Jan Bobrowski <>, 27 Feb 2000 WHOWATCH(1)

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INIT(8) 						      System Manager's Manual							   INIT(8)

init - grandparent of all processes DESCRIPTION
The first program started by Minix is init. The actions performed by init can be summarized by this pseudo shell program: # Open 0, 1, 2. exec </dev/null >/dev/log 2>&1 # Run the system initialization script. sh /etc/rc $bootopts >/etc/utmp echo reboot >>/usr/adm/wtmp while :; do # Wait for a process to exit, but don't always block. wait # Record logout. (Not in this dumb way, of course.) if "pid is in my tables" $pid then echo "logout $pid" >/etc/utmp echo "logout $pid" >>/usr/adm/wtmp fi # Start a new session. while read line type getty init do if idle $line then $init ... <$tty >$tty $getty <$tty >$tty 2>&1 & pid=$! "add pid to tables" $pid echo "login $line $pid" >/etc/utmp echo "login $line $pid" >>/usr/adm/wtmp fi done < /dev/ttytab done The first action of init is to run /etc/rc to initialize the system as described in boot(8). Init then enters its main loop where it waits for processes to exit, and starts processes on each enabled terminal line. The file /etc/ttytab contains a list of terminal devices, their terminal types, the program to execute on them to allow one to login (usually getty(8)), and the program to execute first to initialize the line (usually stty(1)). These fields may be left out to indicate that a line is disabled or that initialization is not necessary. The commands are searched using the path /sbin:/bin:/usr/sbin:/usr/bin. Init accepts several signals that must be sent to process id 1. (It is the first process, so natually its process id is 1.) The signals are: SIGHUP When receiving a hangup signal, init will forget about errors and rescan ttytab for processes to execute. Init normally rescans ttytab each time it feels the need to respawn a process, so the hangup signal is only needed if a line has been shut down, or after a terminate signal. Note that after turning a line off you will have to kill the process running on that line manually, init doesn't do that for you. SIGTERM Normally sent by programs that halt or reboot Minix. Causes init to stop spawning new processes. SIGABRT Sent by the keyboard driver when the CTRL-ALT-DEL key combination is typed. Causes init to run the shutdown command. A second abort signal makes init halt the system directly with a system call. The keyboard driver halts the system, without a sync, after the third CTRL-ALT-DEL. Minix vs. Minix-vmd There are a few differences between standard Minix and Minix-vmd on how init is run. The /etc/rc file is executed under standard Minix with input connected to /dev/console, but under Minix-vmd this is still /dev/null. This means that under Minix-vmd processes must be reconnected to /dev/console with the intr program if they need user interaction. Minix-vmd passes the value of the bootopts boot variable to /etc/rc. Standard Minix does not. FILES
/etc/ttytab List of terminals devices. /etc/utmp List of currently logged in users. /usr/adm/wtmp Login/logout history. SEE ALSO
ttytab(5), utmp(5), getty(8), stty(1), boot(8). AUTHOR
Kees J. Bot ( INIT(8)
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